Imaging apparatus, imaging-displaying apparatus, and control method thereof

ABSTRACT

An imaging apparatus includes an imaging unit, a storage unit, an image processing unit, an image signal output unit, and a timing control unit. The timing control unit generates a first vertical synchronizing signal for driving the imaging unit and supplies the first vertical synchronizing signal to the imaging unit, and generates a second vertical synchronizing signal which is obtained by delaying the first vertical synchronizing signal at least by a predetermined time which is variable according to contents of the image processing performed and supplies the second vertical synchronizing signal to the display unit. The timing control unit controls the image signal output unit so that the image signal is read from the storage unit by being delayed by a phase difference between the first vertical synchronizing signal and the second vertical synchronizing signal, after outputting of the imaging signal from the imaging unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/325,473, filed on Jan. 11, 2017. Thisapplication claims priority to Japan Patent Application No. 2014-148877filed Jul. 22, 2014, the entire disclosures of U.S. patent applicationSer. No. 15/325,473 and Japan Patent Application No. 2014-148877 arehereby incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to an imaging apparatus,imaging-displaying apparatus, and a control method thereof.

BACKGROUND ART

In a so-called mirrorless digital camera, it is possible to check animage of an object using a so-called live view operation in which animage which is imaged using an image sensor such as a Charge CoupledDevice (CCD), or a Complementary Metal-Oxide Semiconductor (CMOS) imagesensor, and corresponding to an image signal is displayed on a liquidcrystal panel which is provided on the rear surface of a housing, anelectronic viewfinder (hereinafter, referred to as EVF) which is builtin at a higher part of the housing, or the like, in real time.

However, in the live view operation, a remarkable delay occurs during atime from imaging of an object using an image sensor to a display on aview finder, or the like. For this reason, it is difficult to cause acamera to face and follow a moving object. In addition, when imaging ofa still image is instructed based on an image of an object which isdisplayed, deviation in timing occurs between the displayed image of theobject and an image of the still image which is imaged, and when it isan object which moves fast, in particular, it is difficult to image adesired still image.

Therefore, an effort of reducing a delay in time from imaging using animage sensor to a display using a display unit such as a view finder hasbeen made.

For example, an imaging-displaying apparatus which is described inJP-A-2007-243615 generates a vertical synchronizing signal which definesan operation timing of the image sensor by generating a signal fordefining an operation timing of a display unit, and by delaying thesignal only for a predetermined time. In this manner, it is possible toshorten a delay in time from a signal output using the image sensor to adisplay of an image based on the signal, by causing a constant phasedifference between the vertical synchronizing signal of the image sensorand a vertical synchronizing signal of the display unit.

SUMMARY

Meanwhile, in general, in an imaging-displaying apparatus, an object isimaged in order of live view→main photographing→quick view→live view. Inthese operations, in any case, an image sensor becomes a reference intiming by being firstly operated. That is, there is not a case in whicha display unit is operated before the image sensor. In addition, when anautomatic exposure or automatic white balance is executed, it ispossible for a user to grasp an image which is photographed in mainphotographing when a processed image is displayed on the display unit,after executing the process by operating the image sensor. For thisreason, it is desirable to operate the image sensor before the displayunit.

However, in the related art, since a signal for defining an operationtiming of the display unit is firstly generated, and a verticalsynchronizing signal of the image sensor is generated thereafter, therewas a problem in that it was not possible to cause reading of the imagesensor to be performed immediately after a generation of a verticalsynchronizing signal of the display unit, and a delay in time occurredwhen displaying an image on the display unit.

The present invention has been made in order to solve the abovedescribed problem, and an object thereof is to shorten a delay in timeuntil an image is displayed on the display unit.

According to one aspect, an imaging apparatus includes an imaging unit,a storage unit, an image processing unit, an image signal output unit,and a timing control unit. The imaging unit outputs an imaging signaldenoting a captured image. The image processing unit generates an imagesignal by performing image processing with respect to the imagingsignal, and writes the image signal in the storage unit. The imagesignal output unit reads the image signal from the storage unit, andoutputs the image signal to a display unit. The timing control unitgenerates a first vertical synchronizing signal for driving the imagingunit and supplies the first vertical synchronizing signal to the imagingunit, and generates a second vertical synchronizing signal which isobtained by delaying the first vertical synchronizing signal at least bya predetermined time which is variable according to contents of theimage processing performed and supplies the second verticalsynchronizing signal to the display unit. The timing control unitcontrols the image signal output unit so that the image signal is readfrom the storage unit by being delayed by a phase difference between thefirst vertical synchronizing signal and the second verticalsynchronizing signal, after outputting of the imaging signal from theimaging unit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram which illustrates a configuration of animaging-displaying apparatus according to an embodiment of the presentinvention.

FIG. 2A is an explanatory diagram which describes a relationship betweenan effective image sensor area and a display area.

FIG. 2B is an explanatory diagram which describes a relationship betweenan effective image sensor area and a display area.

FIG. 2C is an explanatory diagram which describes a relationship betweenan effective image sensor area and a display area.

FIG. 3 is a timing chart for describing operations of theimaging-displaying apparatus.

FIG. 4 is a timing chart for describing operations of theimaging-displaying apparatus.

FIG. 5 is an explanatory diagram for describing the display area.

FIG. 6 is a block diagram which illustrates a configuration of an imagesignal generation unit.

FIG. 7 is a block diagram which illustrates a configuration of a timingcontrol unit.

FIG. 8 is a timing chart for describing operations of theimaging-displaying apparatus.

FIG. 9 is a block diagram which illustrates a configuration of a timingcontrol unit according to a modification example.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described with referenceto drawings. However, in each figure, dimensions and scales of each unitare set to be suitably different from actual dimensions and scales. Inaddition, since the embodiment which will be described below is apreferable specific example of the present invention, the embodiment issubjected to various preferable technical limitations; however, thescope of the present invention is not limited to the embodiment, whenthere is no specific description which limits the invention in thefollowing descriptions.

1. CONFIGURATION OF IMAGING-DISPLAYING APPARATUS

FIG. 1 is a block diagram which illustrates functions of animaging-displaying apparatus 1.

As illustrated in FIG. 1, the imaging-displaying apparatus 1 includes alens unit 10 which forms an image of an object, an imaging unit 20 whichimages the object, and outputs data which is obtained by imaging theobject as an imaging signal DS, an image signal generation unit 30 whichgenerates an image signal D by performing image processing with respectto the imaging signal DS, a display unit 40 which displays an imagecorresponding to the image signal D, a central processing unit (CPU) 50which controls the entire apparatus, an operation unit 60 for inputtinga change in setting of the imaging-displaying apparatus 1, aninstruction of imaging, or the like, a non-volatile memory 61 forstoring a boot program or a phase difference table TBL, a random accessmemory (RAM) 62 which functions as a working region of the CPU 50, amemory card 63 for storing still image data, a VRAM 34 for storing anOSD image signal Dosd, and a timing control unit 70 for generatingvarious timing signals. The CPU 50 generates the OSD image signal Dosdwhich denotes photographing conditions, or the like, such as a shutterspeed, a backlight correction, and a diaphragm value, and stores theimage signal in the VRAM 34 which will be described later. In addition,in the following descriptions, a configuration in which the lens unit 10is excluded from the imaging-displaying apparatus 1 will be referred toas a main body.

The imaging-displaying apparatus 1 is a so-called mirrorless digitalsingle lens reflex camera, and in which it is possible to exchange thelens unit 10. In addition, it is possible to select an operation using alive view mode in which an image related to an object which is imaged inthe imaging unit 20 is displayed on the display unit 40 approximately inreal time due to an operation of the operation unit 60 by a user of theimaging-displaying apparatus 1, and an operation using an imaging modein which an image related to an object which is imaged in the imagingunit 20 is stored in the memory card 63 for storing a still image asstill image data.

The imaging unit 20 includes a mechanical shutter 21, and an imagesensor 22 which line-sequentially scans signals from light receivingelements (imaging elements) which are arranged in a matrix, and outputsthe signals as imaging signals DS corresponding to an object image.

Subsequently, the image signal generation unit 30 includes an imageprocessing unit 31 which generates an image signal D (DGA) based on theimaging signal DS, a VRAM 32 which temporarily stores the image signal D(DGA), and an image signal output unit 33 which outputs the image signalD (DGB) obtained by compositing the image signal D (DGA) which is readfrom the VRAM 32 and the OSD image signal Dosd to the display unit 40.In addition, in the following descriptions, the image signal D (DGB) issimply denoted by the image signal D.

Subsequently, the display unit 40 is an electronic view finder (EVF) forallowing a user of the imaging-displaying apparatus 1 to grasp a stateof an object by displaying an image denoting the object which is animaging target, and includes a liquid crystal panel 42 for displaying animage corresponding to the image signal D which is generated by theimage signal generation unit 30, and an EVF controller 41 which controlsoperations of the liquid crystal panel 42.

A display area AD for displaying an image corresponding to the imagesignal D is provided in the liquid crystal panel 42. The display area ADis configured by including scanning lines of M rows which extend in theX axis direction, data lines of N columns which extend in the Y axisdirection, and pixels of M rows*N columns which are also receivedcorresponding to intersecting of a scanning line and a data line (referto FIG. 2C). In addition, the liquid crystal panel 42 includes ascanning line driving circuit 421 for selecting the scanning line, adata line driving circuit 422 for driving the data line, and an opticalsystem (not illustrated) which magnifies an image displayed on thedisplay area AD so as to be viewed. In addition, each of pixels of Mrows*N columns which is arranged in the display area AD corresponds tocolors of RGB, and can be displayed as a color.

As illustrated in FIG. 2A, in the image sensor 22, a plurality of lightreceiving elements are arranged in a matrix so as to be QS columns inthe X axis direction (horizontal direction), and PS rows (PS lines) inthe Y axis direction (vertical direction) intersecting the X axisdirection in the effective image sensor area AS (PS and QS are naturalnumbers of two or more). In other words, the effective image sensor areaAS is configured so that lines which are formed of QS light receivingelements which are arranged in the X axis direction are aligned by PSrows in the Y axis direction. Each light receiving element generates apixel data signal Sig corresponding to a detected light intensity.

In addition, a color filter of any one color of red, green, and blue isprovided so as to perform one-to-one correspondence with respect to eachlight receiving element. Hereinafter, a set of one light receivingelement and a color filter which is provided corresponding to the onelight receiving element is referred to as a pixel of the image sensor22.

When the imaging-displaying apparatus 1 is operated in an imaging mode,the image sensor 22 can output all of pixel data signals Sig which areoutput from light receiving elements of PS rows*QS columns which areprovided in the effective image sensor area AS as still image imagingdata. In addition, when the still image imaging data is output, theimage signal generation unit 30 which will be described later generatesstill image data by performing various image processes such as afiltering process with respect to the still image imaging data, and thegenerated still image data is stored in the memory card 63 for storing astill image.

Meanwhile, when the imaging-displaying apparatus 1 is operated in thelive view mode, the image sensor 22 reduces a data size of the pixeldata signal Sig by performing a thinning process with respect to thepixel data signal Sig which is output from the light receiving elementsof PS rows*QS columns, and outputs the pixel data signal as the imagingsignal DS corresponding to pixels of P rows*Q columns as illustrated inFIG. 2B (P is a natural number equal to or larger than 2 and equal to orsmaller than PS, Q is natural number equal to or larger than 2 and equalto or smaller than QS).

In addition, the image sensor 22 may include a pixel in an area otherthan the effective image sensor area AS; however, for simplifying thespecification, descriptions of pixels in the effective image sensor areaAS are omitted.

In addition, as illustrated in FIG. 2C, a plurality of pixels arearranged in a matrix so as to be N columns in the X axis direction, andM rows (M lines) in the Y axis direction in the display area AD (M isnatural number equal to or larger than 2 and equal to or smaller than P,N is natural number equal to or larger than 2 and equal to or smallerthan Q), in the liquid crystal panel 42. In other words, the displayarea AD is configured so that lines which are formed of N pixels whichare arranged in the X axis direction are aligned by M rows in the Y axisdirection. These pixels of M rows*N columns include pixels fordisplaying a red color, pixels for displaying a green color, and pixelsfor displaying a blue color. An image corresponding to the image signalD which is generated by the image signal generation unit 30 is displayedin the display area AD.

As described above, M is equal to or smaller than P, and N is equal toor smaller than Q. That is, there is a case in which the number ofeffective pixels which are provided in the effective image sensor areaAS and the number of pixels which are provided in the display area ADare different from each other.

In addition, coordinate systems which are illustrated in FIGS. 2A to 2Care respectively a coordinate system which is fixed to the effectiveimage sensor area AS, a conceptual coordinate system for displaying theimaging signal DS, and a coordinate system which is fixed to the displayarea AD, and a direction of each axis of these three coordinate systemsmay be different from each other.

The above described image signal D is a signal for defining images(gradation) to be displayed using pixels of M rows*N columns which areprovided in the display area AD of the liquid crystal panel 42.Hereinafter, an image signal D of one line which denotes an image to bedisplayed using a line of the mth row of the display area AD among imagesignals D which denote an image to be displayed in the display area ADis denoted by an image signal D[m] (m is natural number equal to orlarger than 1 and equal to or smaller than M).

Subsequently, the timing control unit 70 illustrated in FIG. 1 generatesan imaging vertical synchronizing signal SVsync (first verticalsynchronizing signal), an imaging horizontal synchronizing signalSHsync, and an imaging dot clock signal SCLK (first clock signal),outputs these signals to the image sensor 22, and generates a displayvertical synchronizing signal DVsync (second vertical synchronizingsignal), a display horizontal synchronizing signal DHsync, and a displaydot clock signal DCLK with a frequency different from the imaging dotclock signal SCLK (second clock signal), and outputs these signals tothe EVF controller 41.

FIG. 3 is a timing chart for describing the imaging verticalsynchronizing signal SVsync, the imaging horizontal synchronizing signalSHsync, and the imaging dot clock signal SCLK which are generated by thetiming control unit 70. The imaging vertical synchronizing signal SVsyncis a signal for defining a vertical scanning period Fs (that is, frameperiod of imaging unit 20) for reading the pixel data signal Sig fromlight receiving elements in the entire effective image sensor area AS(PS lines) of the image sensor 22. The imaging horizontal synchronizingsignal SHsync is a signal for defining a horizontal scanning period Hsfor reading the pixel data signal Sig from light receiving elements ofone line of the effective image sensor area AS. The imaging dot clocksignal SCLK is a signal for defining timing for reading the pixel datasignal Sig from a light receiving element of one pixel of the effectiveimage sensor area AS.

FIG. 4 is a timing chart for describing the display verticalsynchronizing signal DVsync, the display horizontal synchronizing signalDHsync, and the display dot clock signal DCLK which are generated by thetiming control unit 70. The display vertical synchronizing signal DVsyncis a signal for defining a vertical scanning period Fd (that is, frameperiod of display unit 40) for displaying an image of pixels of theentire display area AD (M lines) of the liquid crystal panel 42. Thedisplay horizontal synchronizing signal DHsync is a signal for defininga horizontal scanning period Hd for displaying an image using pixels ofone line of the display area AD. The display dot clock signal DCLK is asignal for defining timing for displaying an image using each pixel ofthe display area AD.

According to the embodiment, duration of the vertical scanning period Fsin the image sensor 22, and duration of the vertical scanning period Fdin the display unit 40 are set to be equal. On the other hand, durationof the horizontal scanning period Hs and duration of the horizontalscanning period Hd are set to be different from each other.

In addition, the timing control unit 70 outputs various timing signalswith respect to the image signal generation unit 30, and the imagingvertical synchronizing signal SVsync, the imaging horizontalsynchronizing signal SHsync, the imaging dot clock signal SCLK, thedisplay vertical synchronizing signal DVsync, the display horizontalsynchronizing signal DHsync, and the display dot clock signal DCLK areincluded therein.

FIG. 5 is an explanatory diagram for describing a relationship betweenvarious signals which are generated by the timing control unit 70 anddisplay timing of an image in the display area AD of the liquid crystalpanel 42.

As illustrated in the figure, pixels of M rows*N columns from the lineof the first row to the line of the Mth row in the display area ADdisplay an image of one screen which is denoted by image signals D[1] toD[m] in a vertical effective data period DVI in a vertical scanningperiod Fd.

In addition, N pixels which configure a line of the mth row in thedisplay area AD display an image denoted by the image signal D[m] in thehorizontal effective data period DHI in a horizontal scanning period Hd.

FIG. 6 is a block diagram which illustrates a configuration of the imageprocessing unit 31. As illustrated in the figure, the image processingunit 31 includes line buffer 311 which temporarily stores the imagingsignal DS which is output from the image sensor 22, a pixelcomplementing processing unit 312 which performs a color informationcomplementing process of omitted color information with respect to theimaging signal DS which is stored in the line buffer 311, a colorreproduction processing unit 313 which performs a color reproductionprocess (calculation process of 3*3 matrices) with respect to thecomplemented imaging signal DS, a filtering processing unit 314 whichperforms a filtering process with respect to the imaging signal DS whichis subjected to the color reproduction, a gamma correction unit 315which performs a gamma correction with respect to the imaging signal DSwhich is subjected to the filtering process, a line buffer 316 whichtemporarily stores the imaging signal DS which is subjected to the gammacorrection, and a resizing processing unit 317 which performs a resizingprocess in which the imaging signal DS which is stored in the linebuffer 316 is converted into image signals D of the number of pixelsincluded in the display area AD.

As described above, the number of pixels of an image denoted by theimaging signal DS, and the number of pixels of an image denoted by theimage signal D (the number of pixels in display area AD) are differentfrom each other. For this reason, a resizing process of converting theimaging signal DS into an image signal D corresponding to the number ofpixels in the display area AD is executed in the resizing processingunit 317.

There is a case in which an image denoted by the imaging signal DSincludes various aberrations such as distortion aberration or chromaticaberration which is caused by optical characteristics of the lens unit10. As the distortion aberration, specifically, there is barrelaberration in which an image which denotes an imaging result whenimaging an object expands toward the outside compared to an image to beoriginally displayed in the display area AD, or pincushion aberration inwhich an image is contracted toward the inside compared to an image tobe originally displayed.

In addition, chromatic aberration is a phenomenon in which, when animage is formed through a lens, an image forming position is shifted dueto a color; however, there is axial chromatic aberration in whichfocusing fails in each color, and there is a color blur in an image, andchromatic aberration of magnification in which image height is shifted(magnification is changed) when there is a change in principal point orfocal distance due to a color. Both are caused by a difference in colorwavelength of a ray component and a difference in refractive index oflenses. In a telephoto lens, the axial chromatic aberration easilyoccurs, and in a wide-angle lens, the chromatic aberration ofmagnification easily occurs. With respect to the chromatic aberration ofmagnification, when the image height increases, magnification becomeslarge in light with a long wavelength, and color shift increases at theperipheral portion of a screen. For this reason, in the resizingprocessing unit 317, a distortion aberration correction process in whichdistortion aberration such as barrel aberration, pincushion aberration,or the like, is corrected, and a chromatic aberration correction processin which chromatic aberration (particularly, chromatic aberration ofmagnification) is corrected are executed in the resizing process. Whenthe resizing process is finished, and an image signal D is generated ineach line, the resizing processing unit 317 stores the generated imagesignal D[m] of one line in the VRAM 32.

A degree of distortion aberration changes according to a parameterrelated to optical characteristics such as a type of the lens unit 10, afocal distance or a zooming rate, a diaphragm value, a focusing value,or the like (in particular, type of lens unit 10, and focal distance orzooming rate). Accordingly, it is preferable to obtain a parameterrelated to optical characteristics from the lens unit 10, and to changecontents of the distortion aberration correction process.

It is preferable that a time from outputting of an imaging signal DSfrom the imaging unit 20 to outputting of an image signal D to thedisplay unit 40 is short, since it is possible to shorten a displaydelay. Meanwhile, a time which is necessary for the above describedimage processing is changed according to contents of the distortionaberration correction process and the chromatic aberration correctionprocess which are performed in the resizing processing unit 317. Asdescribed above, the timing control unit 70 generates the imagingvertical synchronizing signal SVsync, the imaging horizontalsynchronizing signal SHsync, and the imaging dot clock signal SCLK whichcontrol the image sensor 22, and generates the display verticalsynchronizing signal DVsync, the display horizontal synchronizing signalDHsync, and the display dot clock signal DCLK which control the displayunit 40.

Here, starting of the frame of the imaging signal DS is defined usingthe imaging vertical synchronizing signal SVsync, and starting of theframe of the image signal D is defined using the display verticalsynchronizing signal DVsync. Therefore, it is possible to shorten adisplay delay while securing a time necessary for the aberrationcorrection process by changing a phase difference between the imagingvertical synchronizing signal SVsync and the display verticalsynchronizing signal DVsync according to contents of the distortionaberration correction process and the chromatic aberration correctionprocess which are executed in the resizing processing unit 317.

According to the embodiment, the CPU 50 obtains optical characteristicdata Docp including a parameter related to optical characteristics fromthe lens unit 10. In addition, the optical characteristic data Docp, thephase difference TD, and contents of image processing are stored in thephase difference table TBL which is stored in the non-volatile memory 61by being correlated with each other. The phase difference TD is a timedifference between the imaging vertical synchronizing signal SVsync andthe display vertical synchronizing signal DVsync, and denotes a timedifference between starting of the frame of the imaging signal DS andstarting of the frame of the image signal D. The CPU 50 specifies thephase difference TD corresponding to the optical characteristic dataDocp, and contents of image processing by referring to the phasedifference table TBL. The CPU 50 generates a correction process controlsignal CTL which designates contents of the distortion aberrationcorrection process and the chromatic aberration correction process,supplies the signal to the resizing processing unit 317, and suppliesthe phase difference TD to the timing control unit 70.

A specific configuration of the timing control unit 70 will be describedwith reference to FIG. 7. As illustrated in FIG. 7, the timing controlunit 70 includes a first timing generator 70A and a second timinggenerator 70B. The first timing generator 70A includes an imaging dotclock signal generation unit 71 which generates the imaging dot clocksignal SCLK, and an imaging synchronizing signal generation unit 72which generates the imaging vertical synchronizing signal SVsync and theimaging horizontal synchronizing signal SHsync based on the imaging dotclock signal SCLK.

In addition, the second timing generator 70B includes a display dotclock signal generation unit 73 which generates the display dot clocksignal DCLK, a display synchronizing signal generation unit 74 whichgenerates the display vertical synchronizing signal DVsync and thedisplay horizontal synchronizing signal DHsync based on the display dotclock signal DCLK, and a reading timing signal generation unit 75 whichgenerates a reading timing signal RTS which designates timing forreading the image signal D from the VRAM 32. In addition, the displaysynchronizing signal generation unit 74 includes a display verticalsynchronizing signal generation unit 741, and a display horizontalsynchronizing signal generation unit 742.

The display vertical synchronizing signal generation unit 741 generatesthe display vertical synchronizing signal DVsync by delaying the imagingvertical synchronizing signal SVsync by the phase difference TD. Thephase difference TD may be determined according to an image processingtime in the image processing unit 31. That is, when the image processingtime is short, the phase difference TD is set to be small, and when animage processing time is long, the phase difference TD is set to belarge.

The display vertical synchronizing signal generation unit 741 may haveany configuration when it is possible to generate the display verticalsynchronizing signal DVsync by delaying the imaging verticalsynchronizing signal SVsync by the phase difference TD using the displaydot clock signal DCLK. For example, it may be a configuration in which arising edge of the display dot clock signal DCLK is counted using acounter which is reset when the imaging vertical synchronizing signalSVsync becomes active, a pulse which becomes active when a countingresult reaches a predetermined number is generated, and the displayvertical synchronizing signal DVsync is generated based on the pulse.

Alternatively, it may be a configuration in which a divided clock signalwhich is obtained by dividing the display dot clock signal DCLK isgenerated, the signal is supplied to K clock input terminals of a IDflip-flop which are subjected to cascade connection, the imagingvertical synchronizing signal SVsync is supplied to the D flip-flop inthe first stage, and an output signal of each ID flip-flop is output byselecting the output signal according to the phase difference TD. Forexample, when one cycle of the divided clock signal is Tclk, and a timenecessary for image processing is Tx, a value Z which is obtained byoperating Tx/Tclk, and by rounding up a decimal point may be set to thephase difference TD. In this manner, it is possible to generate thedisplay vertical synchronizing signal DVsync in which the imagingvertical synchronizing signal SVsync is delayed at least by apredetermined time which is necessary for image processing.

The reading timing signal generation unit 75 generates the readingtiming signal RTS by delaying the display vertical synchronizing signalDVsync by the display dot clock signal DCLK, and supplies the readingtiming signal RTS to the image signal output unit 33. The reading timingsignal RTS controls the image signal output unit 33 so that the imagesignal D is read from the VRAM 32 by being delayed by the phasedifference TD between the imaging vertical synchronizing signal SVsyncand the display vertical synchronizing signal DVsync, after the imagingsignal DS is output from the imaging unit 20.

Subsequently, the display horizontal synchronizing signal generationunit 742 which is illustrated in FIG. 7 generates one display horizontalsynchronizing pulse by counting a predetermined number of the displaydot clock signals DCLK from a falling edge of the display verticalsynchronizing signal DVsync, and may generate the display horizontalsynchronizing signal DHsync by repeating the above described process.

FIG. 8 illustrates timing charts of the imaging vertical synchronizingsignal SVsync, the imaging signal DS, the display vertical synchronizingsignal DVsync, and the image signal D when the phase differences TD aredeltaT1 and deltaT2. Here, a time to is a start time of a frame of theimaging signal DS, a time t1 is a start time of a frame of the imagesignal D when the phase difference TD is deltaT1, and a time t2 is astart time of a frame of the image signal D when the phase difference TDis deltaT2.

When the phase difference TD is deltaT2, it is, for example, a case inwhich an aberration correction process is not performed in the resizingprocessing unit 317. In this case, since the aberration correctionprocess is not performed, the imaging signal DS which is written in theline buffer 316 is immediately read in the resizing processing unit 317,is resized, and is stored in the VRAM 32. In addition, duration of aframe period of the display unit 40 becomes the same duration of a frameperiod of the image sensor 22, and the image signal D is read from theVRAM 32 so that a time until the image signal D is output to the displayunit 40 after the imaging signal DS is supplied to the image signalgeneration unit 30 becomes deltaT2.

When the phase difference TD is deltaT1 is, for example, a case in whichthe aberration correction process is performed in the resizingprocessing unit 317. In this case, imaging signals DS by the number oflines which is necessary for processing are stored in the line buffer316 in order to perform the aberration correction process. In addition,the resizing processing unit 317 generates the image signal D fordisplaying with reference to the stored imaging signal DS, and storesthe image signal D in the VRAM 32. In this case, since a line of theimaging signal DS to be referred to according to a position of a line ofthe image signal D as a processing target is different, generationtiming of the image signal D is changed according to a line in theframe. Here, a time necessary for the aberration correction processbecomes the maximum when the number of lines of the imaging signal DS tobe referred to in order to generate the image signal D according to theline in the frame becomes the maximum. When the maximum time is set totmax, deltaT1 becomes deltaT2+tmax. That is, when the image signals D[1]to D[M] of the first to mth lines are generated, the phase difference TDis determined by taking into consideration a maximum time tmax which isa processing time of a line with the maximum number of reference lines.

In this manner, according to the embodiment, the display verticalsynchronizing signal DVsync is generated by delaying the imagingvertical synchronizing signal SVsync by the phase difference TD, and thedisplay unit 40 is controlled using the display vertical synchronizingsignal DVsync. For this reason, the image signal output unit 33 readsthe image signal D from the VRAM 32 in synchronization with the displayvertical synchronizing signal DVsync, and supplies the image signal D tothe display unit 40.

In this manner, it is possible to set the phase difference TD from astart of a frame in the imaging unit 20 to a start of a frame of thedisplay unit 40 according to contents of image processing, and toappropriately control a delay in time from imaging to displaying, whilesecuring a time for image processing.

In addition, according to the embodiment, first, the imaging verticalsynchronizing signal SVsync for controlling the imaging unit 20 isgenerated, and then the display vertical synchronizing signal DVsync forcontrolling the display unit 40 is generated by delaying the imagingvertical synchronizing signal SVsync. For this reason, it is possible toset duration of the frame period of the imaging unit 20 so as to matchduration of the frame period of the display unit 40. It is possible tosuppress deterioration in quality of a display image by putting theframe period of the imaging unit 20 before the frame period of thedisplay unit 40.

In addition, when the display vertical synchronizing signal DVsync isfirstly generated, and the imaging vertical synchronizing signal SVsyncis generated thereafter, by delaying the display vertical synchronizingsignal DVsync, it is not possible to generate the imaging signal DS, andto display an image immediately after supplying power, even when theimaging unit 20 can be operated. In contrast to this, it is possible torapidly display an image immediately after supplying power, bygenerating the display vertical synchronizing signal DVsync by delayingthe imaging vertical synchronizing signal SVsync.

In addition, in the imaging-displaying apparatus 1, in general, anobject is photographed in order of live view→main photographing→quickview→live view. In these operations, in any case, the image sensor 22becomes a reference in timing by being firstly operated, and there isnot a case in which the display unit 40 is operated before the imagesensor 22. In addition, when an automatic exposure or automatic whitebalance is executed, it is possible for a user to check an image whichis obtained in main photographing when the image is displayed on thedisplay unit 40, after executing these processes by operating the imagesensor 22. According to the embodiment, since the image sensor 22 isoperated by generating the imaging vertical synchronizing signal SVsync,firstly, and then the display unit 40 is operated by generating thedisplay vertical synchronizing signal DVsync, it is possible to rapidlydisplay an image in the display unit 40.

2. APPLICATION EXAMPLES

In the above described embodiment, the imaging-displaying apparatus 1 isdescribed as an example of the mirrorless digital single reflex camera;however, the imaging-displaying apparatus 1 can be applied to variouselectronic apparatuses.

Application Example 1

The imaging-displaying apparatus 1 can be applied to a digital camera inwhich the lens unit 10 is not exchanged. In this case, contents of theaberration correction process and the phase difference TD may bedetermined according to at least one of parameters related to opticalcharacteristics of the lens unit 10 such as a focal distance, a zoomingrate, a diaphragm value, or a focusing value.

Application Example 2

The imaging-displaying apparatus 1 may be applied to electronicbinoculars or an electronic telescope in which magnification isvariable. In this case, it is possible to make the shortest delay intime from imaging to displaying by changing contents of the aberrationcorrection process, and determining the phase difference TD along withthis according to a magnification (parameter related to opticalcharacteristics of lens).

Application Example 3

When an electronic imaging-displaying system is used instead of a sidemirror or a rear-view mirror which is used in a vehicle, the abovedescribed imaging-displaying apparatus 1 may be applied as theimaging-displaying system. In the imaging-displaying system in avehicle, it is necessary to take into consideration that a vehicle movesat high speed. That is, it is important to shorten a delay in time fromimaging of the object using the image sensor 22 to displaying an imagein the display unit 40 for safe driving. When the above describedimaging-displaying apparatus 1 is used, it is possible to make theshortest delay in time from imaging to displaying by changing contentsof the aberration correction process according to magnification which ischanged using an optical zoom, similarly to the electronic binoculars orthe electronic telescope, and determining a phase difference TDaccording to the changed contents.

3. MODIFICATION EXAMPLES

The above described each embodiment can be variously modified. Specificmodification forms will be exemplified below. Two or more forms whichare arbitrarily selected from the following examples can beappropriately combined in a range of not conflicting with each other. Inaddition, in the modification examples which are described below,descriptions of points common to the above described embodiment of thepresent invention will be omitted in order to avoid redundantdescriptions.

Modification Example 1

In the above described embodiment, the timing control unit 70 generatesthe display vertical synchronizing signal DVsync by delaying the imagingvertical synchronizing signal SVsync according to the display dot clocksignal DCLK; however, the invention is not limited to this, and when itis possible to generate the display vertical synchronizing signal DVsyncby delaying the imaging vertical synchronizing signal SVsync at least bya predetermined time which is necessary for image processing, it may beany method.

For example, the timing control unit 70 may be configured as illustratedin FIG. 9. The first timing generator 70A in the example includes adelay vertical synchronizing signal generation unit 721. The delayvertical synchronizing signal generation unit 721 generates a delayvertical synchronizing signal Vds by delaying the imaging verticalsynchronizing signal SVsync by the phase difference TD using the imagingdot clock signal SCLK.

Subsequently, the display synchronizing signal generation unit 74includes a latch circuit 743 instead of the display verticalsynchronizing signal generation unit 741. The latch circuit 743generates the display vertical synchronizing signal DVsync by latchingthe delay vertical synchronizing signal Vds using the display dot clocksignal DCLK.

Modification Example 2

In the above described embodiment and modification examples, the case inwhich the display unit 40 includes the liquid crystal panel 42 has beenexemplified; however, the invention is not limited thereto, and adisplay element such as an organic light emitting diode (OLED) panel,and a plasma display panel may be used.

Modification Example 3

In the above described embodiment and modification examples, a datatransmission between the image signal generation unit 30 and the displayunit 40 is performed using the parallel interface; however, the datatransmission may be performed using a serial interface of low voltagedifferential (LVDS).

Modification Example 4

In the above described embodiment and modification examples, the displayunit 40 is accommodated in the imaging-displaying apparatus 1; however,the invention is not limited to this, and the display unit 40 may beconfigured as a finder (display device), or the like, which is connectedto the outside of a digital camera.

According to an aspect of the present disclosure, there is provided animaging apparatus which includes an imaging unit which outputs animaging signal denoting a captured image; a storage unit; an imageprocessing unit which generates an image signal by performing imageprocessing with respect to the imaging signal, and writes the signal inthe storage unit; an image signal output unit which reads the imagesignal from the storage unit, and outputs the signal to the displayunit; and a timing control unit which generates a first verticalsynchronizing signal for driving the imaging unit, and supplies thesignal to the imaging unit, generates a second vertical synchronizingsignal which is obtained by delaying the first vertical synchronizingsignal at least by a predetermined time which is necessary for the imageprocessing, and supplies the signal to the display unit, and controlsthe image signal output unit so that the image signal is read from thestorage unit by being delayed by a phase difference between the firstvertical synchronizing signal and the second vertical synchronizingsignal, after outputting of the imaging signal from the imaging unit.

According to the aspect, the first vertical synchronizing signal whichcontrols the imaging unit is firstly generated, and the second verticalsynchronizing signal which controls the display unit is generated bydelaying the first vertical synchronizing signal. Accordingly, since itis possible to cause the imaging unit to be operated before the displayunit, a state can be prevented in which the first vertical synchronizingsignal is not supplied to the imaging unit, and it is not possible tooutput an imaging signal, even when the second vertical synchronizingsignal is supplied to the display unit, and it is possible to display animage on the display unit. As a result, it is possible to shorten adelay in time until an image is displayed on the display unit. Inaddition, since the second vertical synchronizing signal is generated bydelaying the first vertical synchronizing signalby at least apredetermined time which is necessary for image processing, it ispossible to perform a control so that the image processing is punctuallyperformed, and to shorten a delay in time from an output of an imagingsignal from the imaging unit to a display of an image on the displayunit.

In the imaging apparatus, it is preferable that the timing control unitcontrols the image signal output unit so that the image signal is readfrom the storage unit by being delayed by the phase difference betweenthe first vertical synchronizing signal and the second verticalsynchronizing signal, after outputting of the imaging signal from theimaging unit. Since the second vertical synchronizing signal isgenerated by delaying the first vertical synchronizing signal at leastby a predetermined time which is necessary for image processing, thephase difference between the first vertical synchronizing signal and thesecond vertical synchronizing signal is a predetermined time or morewhich is necessary for image processing. Since an image signal is readfrom the storage unit by being delayed by the phase difference afteroutputting of an imaging signal from the imaging unit, it is possible tosupply the image signal after being subjected to the image processing tothe display unit.

In the imaging apparatus, it is preferable that the timing control unitincludes a first timing control unit which generates the first verticalsynchronizing signal based on a first clock signal, and supplies thesignal to the imaging unit, and a second timing control unit whichgenerates the second vertical synchronizing signal which is obtained bydelaying the first vertical synchronizing signal at least by thepredetermined time, using a second clock signal of which a frequency isdifferent from that of the first clock signal, and supplies the secondvertical synchronizing signal to the display unit. According to theaspect, it is possible to cause a predetermined phase difference betweena start of a frame of the imaging unit and a start of a frame of thedisplay unit, even when a frequency of the first clock signal whichcauses the imaging unit to operate is different from a frequency of thesecond clock signal which causes the display unit to operate.

In the imaging apparatus, it is preferable that the timing control unitincludes the first timing control unit which generates the firstvertical synchronizing signal based on the first clock signal, suppliesthe first vertical synchronizing signal to the imaging unit, andgenerates a delay vertical synchronizing signal in which the firstvertical synchronizing signal is delayed at least by the predeterminedtime using the first clock signal, and the second timing control unitwhich generates the second vertical synchronizing signal by latching thedelay vertical synchronizing signal using the second clock signal ofwhich a frequency is different from that of the first clock signal.According to the aspect, it is possible to cause a predetermined phasedifference between the start of the frame of the imaging unit and thestart of the frame of the display unit, even when the frequency of thefirst clock signal which causes the imaging unit to operate is differentfrom the frequency of the second clock signal which causes the displayunit to operate.

According to another aspect of the present invention, there is providedan imaging-displaying apparatus which includes the above describedimaging apparatus, and a display unit which displays an image signalwhich is output from an image signal output unit. According to theaspect, it is possible to shorten a delay in time from imaging todisplaying.

According to still another aspect of the present invention, there isprovided a control method of an imaging-displaying apparatus whichincludes an imaging unit which outputs an imaging signal denoting acaptured image; a storage unit; an image processing unit which generatesan image signal by performing image processing with respect to theimaging signal, and writes the signal in the storage unit; a displayunit; and an image signal output unit which reads the image signal fromthe storage unit, and outputs the signal to the display unit, the methodincluding generating a first vertical synchronizing signal for drivingthe imaging unit, and supplying the signal to the imaging unit;generating a second vertical synchronizing signal by delaying the firstvertical synchronizing signal at least by a predetermined time which isnecessary for the image processing, and supplying the signal to thedisplay unit; and controlling the image signal output unit so that theimage signal is read from the storage unit by being delayed by a phasedifference between the first vertical synchronizing signal and thesecond vertical synchronizing signal, after outputting of the imagingsignal from the imaging unit.

According to the aspect, the first vertical synchronizing signal forcontrolling the imaging unit is firstly generated, and the secondvertical synchronizing signal for controlling the display unit isgenerated by delaying the first vertical synchronizing signal.Accordingly, since it is possible to cause the imaging unit to beoperated before the display unit, a state can be prevented in which thefirst vertical synchronizing signal is not supplied to the imaging unit,and it is not possible to output an imaging signal, even when the secondvertical synchronizing signal is supplied to the display unit, and it ispossible to display an image on the display unit. As a result, it ispossible to shorten a delay in time until displaying of an image on thedisplay unit. In addition, since the second vertical synchronizingsignal is generated by delaying the first vertical synchronizing signalby a predetermined time which is necessary for image processing, it ispossible to perform a control so that the image processing is punctuallyperformed, and to shorten a delay in time from an output of an imagingsignal from the imaging unit to a display of an image on the displayunit.

REFERENCE SIGNS LIST

-   -   1 Imaging-displaying apparatus    -   10 Lens unit    -   20 Imaging unit    -   22 Image sensor    -   30 Image signal generation unit    -   31 Image processing unit    -   32 VRAM    -   33 Image signal output unit    -   40 Display unit    -   41 EVF controller    -   42 Liquid crystal panel    -   50 CPU    -   60 Operation unit    -   70 Timing control unit    -   70A First timing generator    -   70B Second timing generator    -   721 Delay vertical synchronizing signal generation unit    -   741 display vertical synchronizing signal generation unit

What is claimed is:
 1. An imaging apparatus comprising: an imaging unitwhich outputs an imaging signal denoting a captured image; a storageunit; an image processing unit which generates an image signal byperforming image processing with respect to the imaging signal, andwrites the image signal in the storage unit; an image signal output unitwhich reads the image signal from the storage unit, and outputs theimage signal to a display unit; and a timing control unit whichgenerates a first vertical synchronizing signal for driving the imagingunit and supplies the first vertical synchronizing signal to the imagingunit; and generates a second vertical synchronizing signal which isobtained by delaying the first vertical synchronizing signal at least bya predetermined time which is variable according to contents of theimage processing performed and supplies the second verticalsynchronizing signal to the display unit, wherein the timing controlunit controls the image signal output unit so that the image signal isread from the storage unit by being delayed by a phase differencebetween the first vertical synchronizing signal and the second verticalsynchronizing signal, after outputting of the imaging signal from theimaging unit.
 2. The imaging apparatus according to claim 1, wherein thecontents of the image processing performed are contents of theaberration correction process.
 3. The imaging apparatus according toclaim 2, wherein the imaging unit includes lens unit, and wherein thecontents of aberration correction process are determined according to atleast one of parameters related to optical characteristics of the lensunit including a focal distance, a zooming rate, a diaphragm value, afocusing value, or a magnification.
 4. The imaging apparatus accordingto claim 1, wherein the timing control unit includes a first timingcontrol unit which generates the first vertical synchronizing signalbased on a first clock signal, and supplies the first verticalsynchronizing signal to the imaging unit, and a second timing controlunit which generates the second vertical synchronizing signal which isobtained by delaying the first vertical synchronizing signal at least bythe predetermined time, using a second clock signal of which a frequencyis different from that of the first clock signal, and supplies thesecond vertical synchronizing signal to the display unit.
 5. Animaging-displaying apparatus comprising: the imaging apparatus accordingto claim 1; and a display unit which displays an image signal which isoutput from an image signal output unit.
 6. A control method of animaging-displaying apparatus which includes an imaging unit whichoutputs an imaging signal denoting a captured image; a storage unit; animage processing unit which generates an image signal by performingimage processing with respect to the imaging signal, and writes theimage signal in the storage unit; a display unit; and an image signaloutput unit which reads the image signal from the storage unit, andoutputs the image signal to the display unit, the method comprising:generating a first vertical synchronizing signal for driving the imagingunit, and supplying the first vertical synchronizing signal to theimaging unit; generating a second vertical synchronizing signal bydelaying the first vertical synchronizing signal at least by apredetermined time which is variable according to contents of the imageprocessing performed; and controlling the image signal output unit sothat the image signal is read from the storage unit by being delayed bya phase difference between the first vertical synchronizing signal andthe second vertical synchronizing signal, after outputting of theimaging signal from the imaging unit.
 7. The control method of theimaging apparatus according to claim 6, wherein the contents of theimage processing performed are contents of the aberration correctionprocess.
 8. The control method of the imaging apparatus according toclaim 7, wherein the imaging unit includes lens unit, and wherein thecontents of aberration correction process are determined according to atleast one of parameters related to optical characteristics of the lensunit including a focal distance, a zooming rate, a diaphragm value, afocusing value, or a magnification.